The synthesis of water soluble pyrazol-5-one azo-dyes has been achieved. 6′- Aminolactosetriacetonide 9 was selected as the key building block to glyconjugate the pyrazole ring at its 3 position via a carboxamide or via a benzeneamide moiety in position 1 of the heterocycle. Diethyl-3-oxopentandionate 2 led eventually to a bicyclic compound, hampering the glyconjugation coupling process. The values of the molar extinction ...
